A disk apparatus moves a head on a rotating disk-shaped recording medium (hereinafter merely referred to as a disk) in the radial direction of the disk to position at a predetermined track, relative to which the head is scanned to read and write necessary signals. Among such disk apparatus, one using a floating head slider arranged by loading the head on the slider utilizing the principle of a dynamic pressure type pneumatic bearing has been widely used because it allows the clearance between the head and the disk to be held extremely fine and highly accurate. When this floating head slider is used, a so-called contact-start-stop (CSS) system forms an important system in order to simplify and make miniaturized the mechanism of the interior of tile disk apparatus, in which when the disk is not rotating tile slider comes in contact with the disk, as the disk starts to rotate the slider gradually floats up, when the disk is steadily rotating the slider holds a predetermined clearance relative to the disk and as the disk stops rotating the slider touches down on the disk again.
A conventional disk apparatus made according to this CSS system has read and written the information from and on the disk as shown in FIG. 1. That is, the surface of a disk 1 is sectioned into a data area 2 and a CSS area 3 which lies innerer than that, and the information track 4 is previously formed only on the data area 2 while the slider is made to touch down only on the CSS area 4 where no information track is formed to control the position of the slider taken in the radial direction of the disk. This is in order to eliminate the damage of the data area which can be caused by its contact with the slider to prolong the lifetime of the disk. Such a disk apparatus is described in, for example, U.S. Pat. No. 4,907,106.
However, as described above, with the conventional disk apparatus, since the CSS area 3 of the disk 1 intensively and repeatedly comes in contact with the slider, as the number of times of the CSS is increased, a lubricant applied on the surface of the CSS area 3 is removed, and the disk 1 and the slider have often been adhered. Further, since only the CSS area 3 repeatedly comes in contact with the slider, this area has been especially susceptible to the wear and damage leading to the troubles such as head crash or the like. Further, with the conventional disk apparatus, since there is provided the CSS area where no information track is formed, the size of the data area 2 has undergone a limit.